fast back to back sendtos crash arduino due

sendto_reproducer.ino

#include <ccspi.h>
#include <Adafruit_CC3000.h>
#include <SPI.h>  // neede for some reason here too

#include <Arduino.h>

#include "utility/socket.h"

#define ENABLE_NET 1

uint16_t _port = 5005;  // picked at random
uint32_t _addr = 0x6401a8C0;  // 192.168.1.100... laptop addr.  Byte swapped correctly!!

int _socket;

#define ADAFRUIT_CC3000_IRQ   3  // MUST be an interrupt pin!
#define ADAFRUIT_CC3000_VBAT  5  // Can be any pin
#define ADAFRUIT_CC3000_CS    10 // Can be any pin

#include "wifi_credentials.h"  // defines WLAN_SSID and WLAN_PASS strings

// Security can be WLAN_SEC_UNSEC, WLAN_SEC_WEP, WLAN_SEC_WPA or WLAN_SEC_WPA2
#define WLAN_SECURITY   WLAN_SEC_WPA2

#define LISTEN_PORT           7    // What TCP port to listen on for connections.  The echo protocol uses port 7.

#ifdef ENABLE_NET
Adafruit_CC3000 cc3000 = Adafruit_CC3000(ADAFRUIT_CC3000_CS, ADAFRUIT_CC3000_IRQ, ADAFRUIT_CC3000_VBAT,
                         SPI_CLOCK_DIVIDER); // you can change this clock speed
Adafruit_CC3000_Server echoServer(LISTEN_PORT);
#endif

void setup() {

  Serial.begin(115200);


  Serial.println( "test" );
#ifdef ENABLE_NET

  Serial.println(F("\nInitializing wifi..."));
  if (!cc3000.begin())
  {
    Serial.println(F("Couldn't begin()! Check your wiring?"));
    while (1);
  }
  Serial.println(F("\nInitialized..."));

  //uint16_t firmware = checkFirmwareVersion();
  //if (firmware < 0x113) {
  //  Serial.println(F("Wrong firmware version!"));
  //  for(;;);
  //}

  //displayMACAddress();


  Serial.print(F("\nAttempting to connect to ")); Serial.println(WLAN_SSID);
  if (!cc3000.connectToAP(WLAN_SSID, WLAN_PASS, WLAN_SECURITY)) {
    Serial.println(F("Failed!"));
    while (1);
  }

  Serial.println(F("Connected!"));

  Serial.println(F("Request DHCP"));
  while (!cc3000.checkDHCP())
  {
    delay(100); // ToDo: Insert a DHCP timeout!
  }

  /* Display the IP address DNS, Gateway, etc. */
  while (! displayConnectionDetails()) {
    delay(1000);
  }

  // Start listening for connections
  echoServer.begin();


  // Create the UDP socket
  int soc = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
  if (soc < 0) {
    Serial.println("socket() call failed");
    while ( 1 ) ;
  }

  sockaddr_in address;
  memset(&address, 0, sizeof(address));
  address.sin_family = AF_INET;
  address.sin_port = htons(_port);
  address.sin_addr.s_addr = 0; // bind to DHCP-assigned address
  socklen_t len = sizeof(address);
  if (bind(soc, (sockaddr*) &address, sizeof(address)) < 0) {
    Serial.println("bind() call failed");
    while ( 1 ) ;
  }

//  int ip = 0xC0A80164;
//  Serial.print(F("\n\rPinging ")); cc3000.printIPdotsRev(ip); Serial.print("...");
//  int replies = cc3000.ping(ip, 5);
//  Serial.print(replies); Serial.println(F(" replies"));

  _socket = soc;



#endif
}


void sendchar( uint8_t data )
{
#ifdef ENABLE_NET
  sockaddr_in address;
  memset(&address, 0, sizeof(address));
  address.sin_family = AF_INET;
  address.sin_port = htons(_port);
  address.sin_addr.s_addr = _addr;
  socklen_t len = sizeof(address);

  int n = sendto(_socket, &data, 1, 0, (sockaddr*)&address, len);

  if ( n < 0 )
  {
    Serial.println( "sendto error" );
  }

#endif
}


uint8_t message[] = "hey there\n";

void loop() {

  if ( millis() % 5000 == 0 )  // every 5 seconds
  {
    // put your main code here, to run repeatedly:

    Serial.println( "printing" );

    for ( int i = 0; message[i] != '\0'; i++ )
    {
      //delay(1); // need a delay or it will crash
      sendchar( message[i] );
    }

  }

}


/**************************************************************************/
/*!
    @brief  Displays the driver mode (tiny of normal), and the buffer
            size if tiny mode is not being used

    @note   The buffer size and driver mode are defined in cc3000_common.h
*/
/**************************************************************************/
void displayDriverMode(void)
{
#ifdef CC3000_TINY_DRIVER
  Serial.println(F("CC3000 is configure in 'Tiny' mode"));
#else
  Serial.print(F("RX Buffer : "));
  Serial.print(CC3000_RX_BUFFER_SIZE);
  Serial.println(F(" bytes"));
  Serial.print(F("TX Buffer : "));
  Serial.print(CC3000_TX_BUFFER_SIZE);
  Serial.println(F(" bytes"));
#endif
}

/**************************************************************************/
/*!
    @brief  Tries to read the CC3000's internal firmware patch ID
*/
/**************************************************************************/
uint16_t checkFirmwareVersion(void)
{
  uint8_t major, minor;
  uint16_t version;

#ifndef CC3000_TINY_DRIVER
  if (!cc3000.getFirmwareVersion(&major, &minor))
  {
    Serial.println(F("Unable to retrieve the firmware version!\r\n"));
    version = 0;
  }
  else
  {
    Serial.print(F("Firmware V. : "));
    Serial.print(major); Serial.print(F(".")); Serial.println(minor);
    version = major; version <<= 8; version |= minor;
  }
#endif
  return version;
}

/**************************************************************************/
/*!
    @brief  Tries to read the 6-byte MAC address of the CC3000 module
*/
/**************************************************************************/
void displayMACAddress(void)
{
  uint8_t macAddress[6];

  if (!cc3000.getMacAddress(macAddress))
  {
    Serial.println(F("Unable to retrieve MAC Address!\r\n"));
  }
  else
  {
    Serial.print(F("MAC Address : "));
    cc3000.printHex((byte*)&macAddress, 6);
  }
}


bool displayConnectionDetails(void)
{
  uint32_t ipAddress, netmask, gateway, dhcpserv, dnsserv;

  if (!cc3000.getIPAddress(&ipAddress, &netmask, &gateway, &dhcpserv, &dnsserv))
  {
    Serial.println(F("Unable to retrieve the IP Address!\r\n"));
    return false;
  }
  else
  {
    Serial.print(F("\nIP Addr: ")); cc3000.printIPdotsRev(ipAddress);
    Serial.print(F("\nNetmask: ")); cc3000.printIPdotsRev(netmask);
    Serial.print(F("\nGateway: ")); cc3000.printIPdotsRev(gateway);
    Serial.print(F("\nDHCPsrv: ")); cc3000.printIPdotsRev(dhcpserv);
    Serial.print(F("\nDNSserv: ")); cc3000.printIPdotsRev(dnsserv);
    Serial.println();
    return true;
  }
}

udp_console.py

#! /usr/bin/python3
import sys
import socket
import select


UDP_IP = "0.0.0.0"
UDP_PORT = 5005
addr = ( "192.168.1.200", 31000 )


sock = socket.socket(socket.AF_INET, # Internet
                     socket.SOCK_DGRAM) # UDP
sock.bind((UDP_IP, UDP_PORT))

while True:
  # Check for input from either stdin or our socket
 
  activity =  select.select([sys.stdin, sock], [], [], 0)[0]

  if sys.stdin in activity:
    line = sys.stdin.readline()
    if line:
        #print "sending line ", line, " to ", addr, " port ", UDP_PORT
        sock.sendto( line, addr )
  
  if sock in activity:
    data, addr = sock.recvfrom(1024) # buffer size is 1024 bytes
    print "received message:", data, " from ", addr
    sys.stdout.write( data )
    sys.stdout.flush()
    

wifi_credentials.h

#define WLAN_SSID       "your"           // cannot be longer than 32 characters!
#define WLAN_PASS       "login"